<!DOCTYPE html>
<html lang='en'>
<head>
    <meta charset='UTF-8'>
    <meta name='viewport' content='width=device-width, initial-scale=1.0'>
    <title>Document</title>
    <script type='text/javascript' src='js/vue.js'></script>
</head>
<body>
    <div id='app'>
        <input type="text" v-model="score">
        <div v-if="score >= 90">优秀</div>
        <div v-else-if="score >= 80 && score < 90">良好</div>
        <div v-else-if="score >= 70 && score < 80">一般</div>
        <div v-else>不及格，叫你家长来</div>
    </div>
    <script type='text/javascript'>
        var vm = new Vue({
            el: '#app',
            data: {
                score: '请输入成绩成绩'
            }
        });
    </script>
</body>
</html>